title: Parallel two-step phase-shifting digital holograph microscopy based on a grating pair.
abstract: An optical configuration for parallel two-step phase-shifting digital holographic microscopy (DHM) based on a grating pair is proposed for the purpose of real-time phase microscopy. Orthogonally circularly polarized object and reference waves are diffracted twice by a pair of gratings, and two parallel copies for each beams come into being. Combined with polarization elements, parallel two-step phase-shifting holograms are obtained. Based on the proposed configuration, two schemes of DHM, i.e., slightly off-axis and on-axis DHM, have been implemented. The slightly off-axis DHM suppresses the dc term by subtracting the two phase-shifting holograms from each other, thus the requirement on the off-axis angle and sampling power of the CCD camera is reduced greatly. The on-axis DHM has the least requirement on the resolving power of the CCD camera, while it requires that the reference wave is premeasured and its intensity is no less than 2 times the maximal intensity of the object wave.
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Baoli
authors.initials: B
authors.lastname: Yao
authors.forename: Irina
authors.initials: I
authors.lastname: Harder
authors.forename: Junwei
authors.initials: J
authors.lastname: Min
authors.forename: Rongli
authors.initials: R
authors.lastname: Guo
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Zheng
authors.forename: Tong
authors.initials: T
authors.lastname: Ye